Electrically operated saw mill set



Aug- 18, 1959 s. LANDls '2,899,990

ELECTRICALLY OPERATED SAW vMILL SET WORKS'OF THE'IRATCHET TYPE FiledJune 1. 1955 :ssheefs-sheetl STANLEY L. LANDIS ATTORNEY INVENTOR Aug. 18, 1959 s. l.. LANDls ELECTRICALLY OPERATED SAW MILL SET WORKS OF THE RATCHET TYPE Filed .June 1. A1955 3 Sheets-Sheet 2 INVENTO R STANLEY L. LANDI S FIG.4

' ATTORNEY Aug. 18, 1959 5.1i.. LANDIS 2,899,990

ELECTRICALLY OPERATED SAW MILL SET WORKS OF THE RATCHET TYPE Filed June 1, 1955 s sheets-sheet s" n2 |87 vles B INVENTOR STANLEY L. LANDIS ATTORNEY United States Patent j ELECTRICALLY kOPERATEDl SAW MILL SET WORKS OF THE RAI-CHET TYPE Stanley L. Landis, Coopersburg, Pa.

Application June 1, 19'55, SeralNo. 512,483 Claims. (Cl.l *14a-120),v

The present invention relates to sawmills and more 2,899,990 Y Patented Aug 1,8,Y 1,959

' rotatably mountedA onv said framework and spaced from particularly( to the adjustment of' the saw set works for c selecting the thickness of the board or plank to. be sawed.

Heretofore various types of saw set works have been provided for adjusting the relative positionof a log to a saw for controlling the thickness of the board being sawed. Some saw set works have required manual labor for the adjustment by an operator and others' have been partially or entirely power operated. However, these prior art structures have not been entirely satisfactory and the usual sawmill depends largely upon manual labor for obtaining the desired adjustment and has required stopping the carriage in a convenient location for thesawyer to make the necessary adjustment. Consequently, the prior art structures have not satisfactorily solved the problem of obtaining accurate controlled adjustment with a minimum of manual effort.

It is, an object of the present invention to overcome the inadequacies of the prior art and to provide a sawmill with saw set works which can accurately be controlled from a stationary location by a relatively unskilled operator.

Another object of the present invention is to, provide a control for the saw set works by which accurate control of the thickness of the board being cut may be obtained.

A further object is to provide means for rapidly moving the head blocks on the carriage in both forward and reverse. directions.

Another object is to provide for accurate adjustment of the thickness of a board being sawed and to provide for rapid change from an adjustment to saw one thickness of a board to an adjustment to saw adifferent thickness of board.

A further object is to provide a control mechanism adjacent the carriage operating lever so that the Sawyer operating carriage may also. control the adjustment of the knees to select the width of board desired while the carriage is in motion.

Other and further objects will be apparent as the description proceeds and in reference to the accompanying drawings wherein:

Fig. l is a perspective view of saw with the carriage supporting tracks mounted adjacent and parallel thereto and a carriage mounted on the tracks with headblocks for supporting a log and including control mechanism;

Fig. 2, a perspective with parts broken away of the control unit for mounting on the log supporting carriage;

Fig. 3, a sectional yplan view taken online 3-3 of Fig. 2 of the control unit'for mounting on the carriage;

Fig. 4, a fragmentary section taken substantially on line 4.-4 of Fig. 3 and illustrating the pawl guard and the electrical control by which the adjustment for one dilferent thickness of board is obtainedgand Fig. 5', a diagrammatic illustration of the electrical and'. mechanical control system.

lBriell-j/,the present invention comprises a saw, a carlriage mounted for movement past the saw and having a a sawmill showing the saidrst shaft is provided with a lange` sprocket..-y A ehain connecting said large sprocket of the second shaft with the freely rotatable sprocket and clutch'elementA on the first shaft causes, simultaneous rotation of s aid first lmd second shaft when the combination sprocket jagd clutch element is, in engagement with the fixed Vclutch element. Y I' A timing mechanism in the form of a commutator is fixed on-the second shaft and has` a plurality of arcuate segmental shaped contact plates which are engaged by contact points in operative relation to said Contact plates.

- A crank is fixed on the second shaft. A third shaft rotatably mounted in the framework is connected to the sets-works shaft on the carriage, such third shaft having a Iratchet wheel fixed thereon; a` series of pawls is mounted on` an arm rotatably mounted on the third ,Sha-ft to engage the ratchet ywheel whilea 'pitman extends from a; crank fixed onsthe second shaft to the arm supporting the series of pawls. An arcuate shaped guard located betweenthe pawls and the ratchet wheel is mounted on-the third shaft and'is adjustable to control the point of engagement of the pawl'with the ratchet wheel soy that the, fixed throw of the crank can produce variations in the rotation of the thirdshaft. A solenoid operatively connected to the combination clutch and sprocket element on the rst shaft is operatively associatedwith a motor control switch for operating the motor in the forward direction. Means including solenoids are provided for changing the vposition of the pawl guard .andfor maintaining the motor control solenoidV in operative position throughout a complete revolutionlofvsad second shaft and commutator, said; third shaft being positively connected to the means for moving head- .blocks toward and from the path of the saw-whereby the log ,may be accurately moved for cutting a. board' lof 45 :selected thickness from. a 10g, Control means arekpro- Vand reverse movement of the motor for moving the vided adjacent a sawyers station for causing forward headblocks toward and from the saw. Clutching means .arevprovided for causing positive drivingof the third shaft from the first shaft for operation in large. increments. Also, a series of buttons are mounted on the carriage movement control .handle for 'operation by the '-sawyer to. select a' desired thickness of board without requiring other manipulation.

power 1 operation 11.

Referring more particularly to the drawing'pavsawmill yiriclndinga conventional saw blade 10, is mounted for from a conventional source of power A `conventional trackway 12 supports amc'onventional earriagel mounted for longitudinal' movement upon wheels 14 and such carriage has mounted thereon a 'pluralityr of L-sphaped knees 15 which are mounted'for .transversesliding movement in conventional'. guides and carry racks 16 which engage the usualpinion gears-17 fixed on the conventional set shaft 18. YSuch set shaft may be. manually .operated by a conventional ratchet -mechanism 19 vhaving a handle Z0 connected toan'operating rod 21 which may befengaged bya hand-'of'a workman 22. 1`

j The knees carry'the usual dogs and taper attachment and. the. like vfor retaining the log; in proper position.

:The structure described is conventionalandweu known in the' agtand is 'presentlymanufactured 'and soldby the Frick Co., of Waynesboro, Pennsylvania. Upon the carriage of such a sawmill, a framework including horizontal members 23 and 24 carrying ybearings 25 and 26 rotatably supports a first shaft 27 having a driving pulley 28 fixed at one end thereof. An electric motor 29 having a pulley 30 by means of a V-belt 31 drives the irst shaft 27 in the same direction as the motor pulley 30, said motor lbeing supported on suitable uprights 32, 33 and members 34 of the framework.

A second shaft 35 is supported at one end in a bearing 36 mounted on a horizontal angle member 37 which is supported at one end by upright `33 and at its other end by a vertical member 38 extending upwardly from the horizontal member 24, the horizontal member 24 being connected to the horizontal member 23 by angle members 39 and 43. The second shaft 35 is rotatably supported at its other endby a bearing 40 mounted on a horizontal member 41 supported at one end by an angle member 42 which extends upwardly from transverse member 43, the other end of member 41 being supported by upright 44 supported from angle member 39. A sprocket 45 is xedly mounted on the shaft 35 and is connected by a chain 46 to a sprocket portion 47 of a combination sprocket and clutch element freely .rotatable on said first shaft 27. A clutch portion 48 (Fig. 5) cooperates (with a clutch element 49 fixed on the shaft 27. It will be noted that the combination sprocket and clutch element 47 and 48 are somewhat out of line when the clutches are in disengagement as shown in Figs. 3 and and when the clutch elements 48 and 49 are in engagement, the sprocket portion 47 is in substantial alignment with the sprocket 45 so that in operative driving relation the chain is substantially straight.

The combination clutch and sprocket 48, 47 is operated by a conventional fork lever 50 pivotally mounted at 51 on a lateral extension 52 supported from horizontal member 24 by means of a forked bolt 52A, lever 50 being operated by a solenoid hereinafter described.

A timing mechanism in the form of a commutator 53 of insulating material is iixed on the second shaft 35 and carries a plurality of concentric arcuate plate segments 56, 57, `58 `and 59 (Figs. 2, 4 and 5), a plurality of contacts cooperating with the commutator as hereinafter described (segments 56, 57 and 58 being shown only in Figs. 2 and 4 for simplicity).

A crank 60 is xed on shaft 35 yand is connected by a pivot 61 to a pitman 62. A third shaft 63 which may be integral with the saw set shaft 18 or otherwise positively connected thereto is rotatably mounted in a bearing 64 (Fig. 3) suitably supported from the horizontal member 23 on al horizontal element 65 supported by upright 32 and at one end by a longitudinal rail 66.0f the log supported carriage at the other end. A plurality of different length pawls 67 are pivotally mounted on arms 68, 68 which straddle a ratchet wheel 69 xed on shaft 63, the arms 68 being connected by a pivot 69 to the other end of the pitman 62 so that rotation of crank 60 causes oscillation of arms 68, 68 and the pawls 67 thereon.

An arcuate shaped guard 70 is fixed on a U-shaped support -having legs 71, 74 and one leg 71 thereof having an extension 72 which is connected by a tension spring `73 to the iixed member 43 for maintaining the guard 70 in the Vnormal full line position shown in Figs. 4 and 5,

the legs 71 and 74 straddling the ratchet wheel 69 and lying within arms 68, 68. The guard 70 is moved from the full line position to the dotted line position shown in Fig. 4 `and to any desired number of intermediate `positions by means of a pitman 75 pivotally connected at one` `end bypivot 76 tothe arm 71 of the U-shaped guard support and pivotally connected at its other end to a crank `arm 77 which is fixed to a fourth shaft 77A by ,any suitable means, wherebyV rotationV of shaft 77A'will `cause movement of the guard 70 through linkages 77, 175, 76 to vary `the positionn of beak 77B vof the guard 4 and thereby control the point of engagement of pawls 67 with ratchet wheel 69 and consequently the amount of rotation of the lshaft 63 and the movement of headblocks 15, 15, 15.

The initial position of the guard 70 is obtained by an adjustment of a threaded Ibolt 78 (Figs. 2 and 3) which yis threaded into upright 33' :and projects against an arm 79 fixed on the shaft 77A, the spring 73 normally urging the yguard to the full line position and urging the arm 79 against the threaded bolt abutment 78, whereby the initial position of the guard can be accurately controlled. Since the length of the crank 60 is fixed, each revolution of the `shaft 35 produces a denite displacement :of pitman 62 and pawls 67 and the variation in the amount of turning `of shaft 63 being controlled by the position of the guard 70.

For rotating the shaft 77A selected amounts, a plurality of substantially similar arrangements are provided, one such arrangement including an arm 80 freely rotatable on shaft 77A and a collar 81 fixed on the shaft 77 and carrying a lug 82 through which an adjusting crew 83 is threadedly mounted for engagement against the arm 80, whereby predetermined movement of the arm 80 in clockwise direction will permit lost motion until arm 80 contacts the screw 83 and thereafter, clockwise movement of the arm 80 will positively rotate the shaft 77A. The arm 80 is caused to rotate by a pitman 84 which is pivotally connected to the armature 85 of a solenoid 86.

Referring more particularly to Figs. 2, 3 and 5, the

`forked lever 50 of the clutch and sprocket combination u48, 47 embraces a bar 87 which is connected by pivot 92 to an armature 88 of a solenoid 89 and such bar 87 `being slidably mounted at its other end 011 a bearing formed by angle 90. A spring 91 connected to the pivot 92 of the armature 88 and the angle 90 normally urges the armature to its extended position as shown and another spring 93 also connected to the armature pivot 92 is connected tothe outer end of the arm 50 by any suitable means such as a cotter pin 94 whereby the solenoid 89 exerts a resilient force on the clutch, forked lever 50 preventing damage to the clutch and permitting reverse rotation of shaft 27.

Fixedly mounted on the bar 87 is a Z-shaped member 96 having its inner leg 97 in engagement with a switch operating arm 98 iixed to a shaft 99 secured to an insulating plate 100 of a motor operating switch 100A. Closing the switch 100A 4will cause rotation of the motor 29 in a forward direction to move knees 15, 15, 15 to- Ward the saw 10 without reverse rotation of combination clutch and sprocket element 47, 48. When plate contacts 101, 102 engage the plurality of spring contacts 103 of switch 100A the Contact 101 engages three of the spring contacts 103, 103D, 103A and the contact 102 engages three different contacts 103B, 103E, 103C to carry electrical energy to the motor for forward operation as is well understood in electrical arts.

The arm 98 is normally urged in a clockwise direction as viewed in Figs. 2 and 5 by a leaf spring 98A mounted on upright 38 to cause the plate contacts 101 and 102 to make electrical Contact with contacts 103.

`It Vwill be observed that -the leaf spring 98A is of insufficient strength to close the contact 101, 102 against the tension of the spring 91 and, therefore, the contacts 101 and 102 are normally out of contact with spring contacts 103 and the freely rotatable clutch 48 is normally out of engagement with the clutch element 49 iixcd on shaft 27. In this condition it will be evident that the `shaft 27 may be rotated in either direction without protactsr103'; 103A; 103B=andf103, respectively, .which cooperate with the plate-contacts10],.1021 Othercon'- taets 103Dand'103E are Yconnectedto lines AY and-B, Arespectively, through leads'1'11' and 112. The switch 104-is mounted in a casing113i(Fig. 1)-and ay shaft 114 carries alever 115-which may be provided-with footengaging pedals 116, 117 which willl operate the -switch 104to produce forward or reverse rotation,respectively, Iof the 'motor 29, forward rotation of'the-motor-'29 vbeing interpreted to be the feeding movementvvhich would cause the headblocks to move toward the saw and the reverse rotation being that which would'cause the headblocks 4to move away from-the saw.

Continuous forward r`reverse movement of the headblock For moving the headblocks 15, 15 a greater distance, a direct drive between the shaftl 27- and shaft 63 is provided'and the forward and'revers'e motion-of theY motor v29 is accomplished by the switch 104'operated by foot pedals 116 and 117. The shaft 27 is driven as previously explained from the motor 29 through pulley 30-and belt 31 andbelt pulley 28 on shaft 27. However, rotation of shaft 27 does not produce any useful results without operation of one of the clutches thereon. Al clutch element 118 is fixed -to the shaft 27 by any suitable meansand a combination clutch element 119 and sprocket 120V is movedby means of a forked lever12-1 pivoted at 122 to a horizontal member 123'which is fixed to the frame member 122 by a bolt 124. The fork of the lever 121 engages. in agroove 125 of the combination'clutch and'sprocket element. The lever 121 is operated by an ami 126 connected by a pivot 127 to the armature 128 of a solenoidy 1219. It will be apparent that when solenoid 129 has actuated the vclutch element 119 that element engages: clutch element 118, thereby positively connecting the' shaft 27 to the sprocket 120, a chain 130 extending around sprocket 131 aiiixed on the shaft 63 causes a continuous forward or reverse rotation of the shaft 63 in. accordance with the direction of rotation of the motor 29,

Operation Upon reference to Fig. j, the conventional handL lever 132 which controls the feeding and return movement of the log supporting carriage has a lateral extension 133 in. which a plurality of switchessincluding buttons 134, 135, 136 and 137 are located and each of such buttons'engages a spring contact 134A, 135A, 136A, 137A connected together by an electrical conducting leadY 138 which extends to line B of the power supply. Each of the spring contacts cooperates with a corresponding liXed contact 134B, 135B, 136B and 137B, respectively, and such iixed contacts are connected :through suitable leads to other control elements. Contact 134B is designed for the smallest increment of movement of theV headblocks: 15, 15 in which the pawl guard 70 remains in its original position as shown in Figs. 3, 4 and 5. The fixed contact 134B is connected by a lead 139 to one terminal of the solenoid 89 and connected by another lead from the; said one terminal of the solenoid 89 by a lead 140 to anotherlead 141 connected to a one spring contact 142 on" atixed insulated support 143 mounted on bracket 144- on ahorizontally positioned U-shaped frame 145 (Figs.

2, 3 and 4) the horizontal U-shaped frame 145 being suitably supported on the framework. The other spring; contact V146er the lixed insulated support 143 is connected by a lead .147- to a second lead ,148 which is permanently connected to a line A of the power supply.

Assuming that the smallest thickness of board is to be. cut, the operator p resses the button 134` for a suflicientt length of time to carry current from line B through lead 138 and spring contact'134A to ixed contact 134B to lead 139 to the one contact of solenoid ,89, the other connection of solenoid V39being connected by a lead 149 to anarmature 150 of a solenoid' 151`to anotherileadf152 6 permanently connected tov line A-gof the power supply thereby completing a circuit through'y solenoid 89- energizing such solenoid to move the armature 8,81 'and the operatingfbar-87 to a position in'rwhich the Z-shaped element 96 disengages from the arm 98, the arm 98. being spring urged by spring 104`so that plate contact 10-1 makes electrical contact with spring contacts 103, 103D- and 103A, while plate contact 102 makes electrical contact withV spring contacts 103B, 103B and 103C thereby completing a circuit from lines A and Bthrough leads 111, 112 and switch A and through leads 107, 108, 109 andr110V to the motor 29, causing the motor to rotate in a forward direction. Simultaneously, the clutch element 48 is engaged with clutch element 49 and rotation of shaft 27 caused by the motor 29 causes rotation of the clutch'element 48 and the sprocket 47-, Vthe chain 49 4causing sprocket 45 lto be rotated causing rotation vof shaftv 35 which causes the commutator 53 fixed on the shaft 35 to'rotate segmental arcuate shaped plate contact 57r to engage contacts 142 and 146, thereby completing: the circuit from line A-through lead 148, leadf147, contact .146, segmental contact plate 57, contact 142, lead 141,

and lead to solenoid 89 thereby energizing solenoid 89 even though switch 134 isV open since the other'connec- 4tion to solenoid 89 isconnected through lead 149-, arma- VJture and lead 152 to the line A. Therefore, the solenoid 89 remains energized vas long as plate contact 57 remains in contact with spring contacts 142 and 146. As soon as the plate contact 157 runs out from under the :spring contact 142, 146, the solenoid 18,9 is de energized.

It will be understood that the rotation of shaft 35` for ;a complete revolution-results in rotating the crank arm i60 a complete revolution thereby moving pitman 62` and parallelV pawl supporting arms 68 with pawls 67 thereon over the guard 70 until the pawls 67 engage the teeth of ratchet 69 after the pawl 67 passes over the beak 77B of the guard, thereby rotating the ratchet wheel 69a definite :amount and also rotating shaft 63- to which the ratchet wvheel is xed, such shaft 63 causing rotation of the conventional saw set shaft 18, the pinion gears 17 thereon, thereby moving the headblocks 15 toward the saw a detinite amount, for example, one half inch. It willl be apparent that the headblocks 15 Will be moved after the carriage has moved the logs out of the path of the saw 10 so that the log will be moved over the predetermined distance, for example, one half inch, and the next saw :cut can be made by the operator 22 moving the handle 132 in a .direction to cause the carriage tov carrythe log into the path of the saw so that the half inch board may be cut from the log.

Assuming that a board of 11/2 inch thickness is tobe cut, the operator 22 presses the button 136, thereby closing a circuit from line B to lead 138, spring Contact 137A to fixed contact 136B to a lead 153 to solenoid 86 and also from lead- 153 to a lead 154` to a spring contact 155 mounted on a pivoted insulating plate 156 which is pivotally mounted on a supporting shaft 157 mountedv on through from spring contact tov spring contact-158` -until' suchV spring contacts are caused to engagev arcuate Contact segment 58 and this is caused by the energization of solenoid 86 from switch 136 through leadV 153 to. solenoid 86 and thence by lead 160.to lead 161- connected to solenoid 89 and through lead 149, relay switch 150 and lead 152 to line 80. Immediately upon energization of solenoid 86, the armature thereof isdrawn inwardly moving link 84- to the left as viewedfin Figs. 5Y andV 4 causing .an abutment guide 162 on pitman 84 to engage arm v163 of a bell crank lever pivoted at 164 and having the other arm 165 thereof connected to a link '166`which link 166 .is connected by the equivalent of the pivotal' connection 1o an extension 167 on `the insulated plate .156 thereby catusing contacts 1155` and 158-to engage platefcontact 58 completing a circuit which will maintain Vthe solenoid 86 .energized even though push` button 136 is released and spring contact 136A becomes disengagedfrom fixed contact 136B. A laterally extending lug 168 (Fig. 5) is xed on insulating plate 156 and the projecting end thereof engages a pivotal insulating plate 169 which carries a spring contact 170 which` Vis connectedV by a lead 171to lead 140 and to contact 142 of insulating support 143. The other contact 172 on pivoted insulating plate 169 is connected by lead 173 to lead 148 and thence to power line A. Y l i It will be understood that when rod 166 is drawn downwardly pivoting insulating plate 156 causing contacts 155 and 158 toengage segmental plate 58, that insulating plate 169` will also be pivoted about shaft v157 because of engagement by lug `168 on plate 156 thereby causing contacts 170 and 172 to engage segmentalplate 57 and since contacts 170 and 172 are connected parallel with contacts 142 and 146, respectively, of xed insulating plate 143, the solenoid 89 is immediately energized when push button 136 closes the switch contacts 136A, 136B causing the motor 29 to rotate in a forward direction by allowing leaf spring 104 to close switchl 100A and causing the clutch elements 48 and 49 to engage causing rotation of shaft 35 through sprocket elements` 47, 45 and chain 46, the motor switch 100A remaining closed and the solenoid 86 remaining continuously energized by the engagement of spring contacts 155 and 158 with segmental plate 58 which is caused by a downward movement of rod 166 `which is held in its downward position by the solenoid 86.

Solenoid 86 simultaneously moves the arm 80 which is pivotally connected to link 84 until such arm 80 engages adjusting screw 83 and further movement of arm 80 against adjustment screw 83 causes rotation of shaft 64 causing simultaneous movement of arm 77 and movement of link 75 which in turn causes movement of the guard 70 through arms 71 and 74 which are pivotally connected to link 75, thereby withdrawing the guard '70' and moving the same in a counter-clockwise direction as viewed in Figs. 4 and 5, and the beak 77B will be moved a definite distance and will be held thereby the solenoid 86 throughout the cycle. The pawls 67 will be caused to move over the portion of the guard 70 between the pawls 67 and the beak 77B by the action of crank 60 and pitman 62 on pawl supporting arms 68 and the pawls 67 will therefore engage the ratchet wheel 69 over a greater distance because of the withdrawal of the guard 70 relative to the arc of engagement caused by the depression of button 134 and therefore the ratchet wheel 69 will rotate a greater amount upon closing switch 136 than upon closing switch 134 causing a greater rotation of shaft 63 and thereby greater rotation of shaft 18 on the carriage resulting in a movement, for example, of one and one half inches corresponding to an increment of adjustment of 11/2 inches or cutting of a board 11/2 inches thick.

A different thickness of board may be cut by depressing the button 135 and actuating the corresponding switch and through lead 174 and lead 175 to a contact 155A of a pivoted insulating plate 176, lcad 174 continuing to a solenoid 175A which is similar to solenoid 86 and has its other terminal connected to lead 161 to line A. Another lead 177 extends from the other contact 158A of pivoted insulating switch 176 to lead 148 to line B thereby activating the structure ,for a cycle, the operation resulting from closing switch 135 is designed to produce one inch, for example, of movement of the headblocks 15, 15. To cause operation of the insulating plate switch 169, a U-shaped member 178 is xed on the insulating plate 176 and abuts the insulating plate 169 permitting the insulating plate 169 to be moved without causing movement of the insulating plate 176, the U-shaped member 178 corresponding to the lug 169 of insulating plate 156.A

The push button switch 137 is 4connected by a lead 179 to one terminal of a solenoid 180, the other terminal of the solenoid being connected to lead 161 and from lead 179 another lead 181 extends to one contact 155B of a switch 182, the other contact 158B of such switch being connected by lead 183 to lead 148 and thence to line B. The solenoid `operates a bell crank 163B, 165B in a manner similar to' the way solenoid 86 operates bell crank 163, 165. The switch 137 is arranged to produce an incrementofmovement of the headblocks of two inches, for example. Since the operating mechanism from the solenoids 86, 176, and 180 are substantially similar, the corresponding parts of the mechanism activated by solenoids 176 and 180 are described by the use of the same reference numerals used in describing the operations performed by solenoid 86 followed by the letters A or B, respectively, the solenoid 176 and the structure operated thereby being omitted from the drawings except in Fig. 5 to avoid complexity. It will be observed, however, that the number of solenoids 86, 176 and 180 may be increased or decreased as desired to correspond with the diierent numbers of increments of thickness of board desired. It will also be evident that the cycle of adjustment may be repeated for two cycles to obtain a selected adjustment, by adjustment of screws 83, 83A, 83Bthe size of the increments may be changed for greater or less thickness of board.

lt will be observed that when switch 134 is actuated for merely an instant, no appreciable movement of shaft 35 occurs because the energization of solenoid 8 9 depends upon a continuous depression of the switch 134 and the arcuate segmental contact 57 being out of engagement with spring contacts 142 and 146, the contact switch 134 must be held closed a suicient length of time to permit clutch 48, 49 to engage and rotate shaft 35 until the arcuate shaped contact 57 comes into engagement with spring contacts 142 and 146 and thereafter the operation is controlled by the arcuate segment 57 even though the switch 134 is allowed to open and the operation continues until the arcuate segment 57 passes completely past spring contacts 142 and 146 at which time the crank will be substantially in the position shown in Figs. 2, 3 and 4, the shaft 35 being stopped in a denite position at all times'. When one of the other switches 135, 136 and 137 is actuated, a corresponding one of the solenoids 176, 86 and 180 is activated resulting in movement of the pawl guard 70 a denite amount so that pawls 67 will engage the ratchet teeth over a predetermined arcuate movement, When any one of thevswitches 135, 136 and 137 is closed the corresponding solenoids 176, 86, or 186 causing instantaneous activation of insulating plate 169 and closure of contacts 170 and 172 with arcuate segmental plate 57 requiring'the completion of a cycle of operation before the motor 29 is stopped.

The head blocks may also be controlled` by the usual lever 2li having the extension link 21 with a hand-engaging loop 184 by means of which the link may be rotated to disengage certain of the pawls in the conventional Frick Co. ratchet mechanisms of the hand setting set works and receder 185. It is desirable to have the pawls disengaged from the ratchets of the set works when extensive adjustment is made by foot pedals 116 or117 and accordingly a solenoid 186 may be mounted upon the carriage or on a portion of the lever 20 which solenoid 186 actuates an armature 186A connected to a lever 187 which may be pivoted at 18S to a fixed point with the other end 189 engageable with the pawls or the operating mechanism therefore to release the pawls from the corresponding ratchets. The solenoid 186 is energized by switch contacts 190 and 191 between which movable earn-shaped contact 192 is located such cam-shaped` contact being fixed to andA preferably insulated from the shaft 1114 and being so designed as to close a circuit between contacts 190 and 191 before switch 104 can cause actuation of the motor 29 so that the pawls on the set works will be disengaged before the set works -137 will be ineifective.

shaft 18; S-.rotatedY when-mtor- 29 isope'rated by switch circuit from. vContactv 111v .being completed -mentof the head blocks or upon the operator stepping on' pedal i117 to produce rearward adjustment of the headblock's, the switchy 104 being normally open.

A safety device to prevent a short circuit and to prevent anypossibility Aof simultaneous operation of the set works by any of the switches 134 to 137 and the foot `pedals 116 and'.1 17v is provided in the form of a normally closed relay switch 150 connected to power "line A by lead '152, a' lead"149 from relay switch 150 being contnected to one' terminal of the solenoid 89, such relay -switchA 150 is normally closed so that actuation'of any ofl the. switchesy 134-137v will produce the desired ifncre'- ment ofl adjustment as previously described. However, inxthe` event that one ofthe switches 134-137 is closed atfthesame time' that afoot pedal 116 or 117 is depressed, the actuation' produced by the switches 134 or This may be accomplished by energization of solenoid 151 from contacts 190 and 191 byy the depression of either foot pedal 116 or 117, which causes the cam contact 192 to engage contacts 19t) and 191 before. switch 104 is closed, the contact 191 being connected by lead 193 to line B and the contact 190 being connected by lead 194 and lead 196 and a lead 197 to one contactof the vsolenoid 15-1, the other contact of the solenoid 151 being connected by lead 198 to the lead 199 which is connected to lead 195 which in turn is connected to power line A, thereby energizing solenoid 151 and causing the armature 150 thereofY to be drawn to open such4 relay switch 150i, thereby preventing energization of solenoid 89 and preventing actuation ofthe motor 29 by the but-ton switches 134 to 137.

When the foot pedals 116 or 117 are depressed, as stated previously, the cam 192 makes` electrical contact withL contacts 190 and 191 before the switch 104 isV pleting the circuit and causing the clutch 119 to engage and'vth'ere'after the motor switch 104 is actuated and the motorl is started, therebycausing rotation of shaft 27 and sprocket element 120 of clutch element--119 to cause the sprocket 131 to be rotated' causing rotation of shaft 63 androtation of set works shaft 18 and movement of the head blocks-in accordance with the foot pedal being depressed. p

It will therefore be seen that the operator 22 has cornplete control of the entire operation of the sawmill and from hisv single station can produce the' large increments ot'- adjustm'ent of the headblocks ory the accurate measured increments of movement by the use of the switches operated by buttons 134 to 1'37 vand mounted on the handle 132. The handle 132 controls movement of the carriage in 'the usual way. Also` the operator can operate the headblocks manually byuse'ofl the link 21 which can operate the set works and reader in the usual manner.

Ullder tlleftracksA 12fand away from the saw and up to overhead trolley 201 on which a plurality of yokes supported by pulleysridingonthe trolley 201 sup-f portz'coilsofthe. electricat .cable 2,00' 'with' one' end ofthe ,cable extending downwardly throughf or 'along' af post 1203 lto controlmechanism Within the framework. Suchframework and cont-rol is covered by housing 204 whichconcealsv the operating mechanism. The supply of power'is to the control mechanism withl a of interference. It will be apparent that thecontrol circuit could be carried by other means such as conductive trolleys Vor the like, but this arrangement is'believed'to be particularly advantageous since the coils of the cable' 200 may collapse and expand similar to coils of springs,A the trolley wire 291 serving as a' suitable track or support which is well out of the path of the workmen and the logs thereby avoiding danger to the persons in the sawmill and preventing damage to the control system.

The ratchet release solenoid 186 may be mounted di'- A by the reverse movement of the carriage and i-n 'such' arrangement the lwiring is simplifiedv by not requiring' a flexible connection to the solenoid as in the modication inv which' the clutch release solenoid is mounted on the operating handle 20.-

It is contemplated that a three phase 220 volt source of electrical power' (not shown) may be used and reverse switches of a suitable well known type will be used with such power.

Also .the drive from the motor 29 to the shaft 27 may be made through a speed reducer by direct connection without requiring the use of a belt.

It will be obvious to those skilled in the art thatvariousV changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is illustrated inthe drawings and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. A sawmill comprising a saw, a carriage movable forwardly and rearwardly relative to said saw, a plurality of headblocks mounted on said carriage, a slidable knee on each headbloek means on said knees andv carriage to retain a log, means to move saidV knees toward and from said saw for adjustmentof the thickness of aboard being cut from the log, saidl means including a framework structure mounted on said carriage, a motor on said framework, al rst Shaft rotatably mountedon .said

framework and driven from said motor, a secondy shaft mounted on said framework, a sprocket fixed on said second shaft, a freely rotatable combination sprocket and clutch element mounted on said first shaft and slidable thereon, a second clutch element fixed on said rst shaft and cooperable with said combination sprocket and clutch element for positively driving Vthe latter, a chain connecting said sprockets whereby the said sprockets will be driven in timed relation, a commutator fixed on said second shaft, contact points in permanent engagement with saidv commutator, a plurality of movable contacts on said framework for engagement with said commutator, a crankonsaid second shaft,`a.pitman connected to said crank,` a third shaft, aV ratchet wheel xed on said third shaft, a pawl mounted on an arm rotatable on said third shaftfor engagement with the ratchet wheel, said pitman being connected by the armon `which Isaid pawl is mounted, a guard mounted` on said and` advance said ratchet wheel a definite amount, said rthird shaftrbeing positively connected to the means to move 4said knees toward and from the path of the saw whereby the log may be accurately moved for cutting a board therefrom.

2. The invention according to claim l in which manually powered means are also provided for controlling the movement of the knees toward and from the path of the saw. Y

3. The invention according to claim 2 in which means are provided for varying the position of the ratchet guard whereby different thicknesses of board may be eut, and manualrmeans for selecting the position of said ratchet guard.

4. A power control unit for producing a predetermined rotation in a shaft, said control unit including a framework having a motor thereon, a first shaft rotatably mounted in said framework and driven from said motor,

, la second shaft mounted in said framework and positively connectable to said iirst shaft by means of a first clutch, a timing device on said second shaft, a third shaft, means to rotate said third shaft a selected amount upon rotation of said second shaft through a complete rotation, means to actuate said first clutch and energize said motor to initiate a cycle of operation and means for thereafter automatically continuing the cycle by said timing means and upon completion of said cycle said first clutch and motor will be de-energized, and means for operating said third shaft from said motor through a second clutch independently of said timing mechanism and said rst clutch for producing unpredetermined amounts of lrotation of said third shaft, the drive from said motor being directly to said first shaft.

5. A power control unit for producing a predetermined rotation in a shaft on a movable carriage from a stationary control station, said control unit including a framework having a motor thereon, a first shaft rotatably mounted in said framework and driven from said motor, a second shaft mounted in said framework and positively connectable to said first shaft by means of a clutch to rotate said second shaft a complete rotation, a timing device on said second shaft, a third shaft, means to rotate said third shaft a selected amount upon rotation of said second shaft through a complete rotation, and means to aetuate said clutch and energize said motor to initiate a cycle of operation and means for thereafter automatically continuing the cycle by said timing means and upon completion of said cycle said clutch and motor will be deenergized, and means at the control station for initiating the actuation of said clutch and the energizing of said motor, and for predetermining the extent of rotation of said third shaft.

6. The invention according to claim 5 in which other means are provided for operating said third shaft from said motor independently of said timing device and said first clutch for producing unpredetermined amounts of rotation of said third shaft.

7. A control unit for application to a sawmill having a fixed saw, a movable carriage with knees for supporting a log for movement toward and from the saw, and manually powered ratchet means to move the knees toward the saw, said control system including a unit for mounting on the carriage, power operated means on the unit for moving said knees toward and from the saw, a controlV for location adjacent the saw blade, said control including Y means tooperate said power operated knee moving means on the carriage a definite predetermined selected amount, means to move the knees toward and from the saw an unpredetermined amount, and means to Vautomatically release 'the ratchets of said manually powered means when the control means for moving the knees an unpredetermined amount is operated.

8. Automatic adjusting means comprising a framework, a motor mounted on said framework, said motor driving a first shaft through speed reduction means, a second shaft mounted on said framework, control means to initiate operation of said motor and continue the operation of the motor for a complete turn of said second shaft, a crank mounted on said second shaft, `athird shaft for positive connection to the shaft for moving the knees on the headblocks of a carriage toward and from the saw, a ratchet wheel on said third shaft, and pawl means operated by said crank for moving said Iratchet forwardly to rotate said third shaft a denite amount for each rota'- tion of said second shaft, and means whereby rotation of said third shaft can be varied from said definite amount for producing movement of the'knees to obtain a board of different thickness.

9. The invention according `to'claim 8y in which means are provided for alternatively directly connecting'said motor to said third shaft to produce adjustments of indeterminate extent.

10. Knee adjusting means for a carriage comprising a framework, a motor mounted on said framework for producing rotary motion, a crank shaft mounted for rotation on said framework, a crank on said crank shaft control means to cause operation of said motor to produce one revolution of said 'crank shaft and stop, a pitman connected to said crank, `a pawl operated by said pitman, a shaft having a circular ratchet mounted on said framework, said pawl cooperating with said ratchet whereby the reciprocation of said pawl by said crank will cause a definite rotation of said shaft having a ratchet, vand means selectively operable whereby said pawl may be engaged or disengaged from said ratchet at pre-determined selected positions whereby the extent of rotation of said ratchet shaft can be definitely controlled for each revolution of said crank shaft.

1l. The invention according to claim 10 in which means are provided whereby the same motor may serve to rotate said ratchet shaft through a separate train of mechanism without operation of said crank shaft.

l2. The invention according to claim 10 in which a guard is provided for normally holding the pawl out of contact with said ratchet and the position of the guard can be controlled to vary the effective arc of movement of the pawl while in contact with said ratchet.

13. Knee adjusting means for log engaging knees of a carriage of a sawmill comprising a framework for mounting on the carriage, a motor mounted on said framework, a rst shaft `rotatably mounted on said framework `and driven from said motor, a second shaft mounted on said framework, a first clutch between said first shaft and said second shaft for driving said second shaft, a commutator fixed on said second shaft, contact points for engagement with said commutator, a solenoid for operating said clutch on said first shaft, a switch connectedA to said first clutch solenoid, means for causing said motor to rotate in a forward direction and means to actuate said first solenoid, said commutator and said contact points serving thereafter to continue the energization of said first solenoid and said motor `for a pre-determined extent of rotation of said second shaft whereby the knees of the carriage will be advanced a definite amount for moving the knees of the carriage a definite amount toward the saw, whereby a log may be accurately moved for cutting a -board therefrom.

14. Saw set works adjusting means comprising a framework, a motor mounted on said framework, said motor driving a first shaft through speed reduction means, a second shaft mounted on said framework, commutator means on said second shaft connectable to control said motor, contact points mounted on said framefor engagement with said commutator for controlling said motor to produce a complete rotation of said second shaft, means for operating said motor, a crank mounted on said second shaft, a third shaft for positive connection to the shaft for moving the knees on the headblocks of i 'si' a carriage toward and from the saw, a ratchet wheel on said third shaft, and pawl means operated by said crank for moving said ratchet forwardly to rotate said third shaft a definite amount `for each revolution of said second shaft, and means Ito control the eiective engagement of said pawl means with said ratchet an'd thereby the extent of rotation of said third shaft by a complete rotation of said second shaft.

15. A control unit `for application to a sawmill having a fixed saw, a movable carriage with knees for support- Ving a log Vfor movement toward and from the saw and means to adjust the knees, said control system including a unit for mounting on the carriage, means on the unit for moving the knees of the sawmill toward and from the saw blade, a control for the movement of said knees toward and from the saw and adapted for location adjacent the saW and off the carniage, said control including means to operate the -unit on the carriage to move the knees a denite pre-determined amount according to a certain actuator and separate means .to move Ithe knees toward and from the saw any unpredetermined amount under the control of the operator, and means to prevent simultaneous actuation of the control means to operate the knees a definite predetermined amount and to prevent the simultaneous actuation of the References Cited in the file of this patent UNITED STATES PATENTS 24,913 Smith et al July 26, 1859 493,546 Dodge Mar. 14, 1893 660,045 Carroll Oct. 16, 1900 857,663 Osborn June 25, `1907 1,725,861 Grueter Aug. 27, 1929 1,846,687 Mentor Feb. 23, 1932 2,125,371 Field Aug. 2, 1938 2,355,381 Lear Aug. 8, 1944 2,561,346 De Vlieg et al. July 24, 1951 2,574,393v Hult NOV. 6, 1951 2,597,355 Masuy May 20, 1952 2,661,036 Balch et al. Dec. 1, 1953 2,696,853 Balch et a1. Dec. 14, 1954 2,721,588 Roberts Oct. 25, 1955 

